81600873617 has 2 divisors, whose sum is σ = 81600873618. Its totient is φ = 81600873616.

The previous prime is 81600873581. The next prime is 81600873619. The reversal of 81600873617 is 71637800618.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 73720938256 + 7879935361 = 271516^2 + 88769^2 .

It is a cyclic number.

It is not a de Polignac number, because 81600873617 - 2²⁴ = 81584096401 is a prime.

Together with 81600873619, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81600873619) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40800436808 + 40800436809.

It is an arithmetic number, because the mean of its divisors is an integer number (40800436809).

Almost surely, 2^81600873617 is an apocalyptic number.

It is an amenable number.

81600873617 is a deficient number, since it is larger than the sum of its proper divisors (1).

81600873617 is an equidigital number, since it uses as much as digits as its factorization.

81600873617 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 338688, while the sum is 47.

The spelling of 81600873617 in words is "eighty-one billion, six hundred million, eight hundred seventy-three thousand, six hundred seventeen".